This book was full of interesting discussion - probably my favorite was about studies looking at the effect of the agism stereotype. In one of them older folks were put inside a renovated hotel made to look 30-40 years old (as in, all the newspapers and fashion etc was of that time), and the people were told to imagine themselves to be living in the past (rather then just to reminisce about it) - and those folks got measurably more flexible and healthy in a matter of weeks. We all think old people are falling apart and unhealthy, and our brain actually projects that onto ourselves as we age. Literally, just thinking you're younger can have very positive physical effects!